Field of the Invention
Example embodiments relate generally to a system and method for controlling an operation of an application by classifying an application type for data bearers based on data bearer characteristics.
Related Art
FIG. 1 illustrates a conventional 3rd Generation Partnership Project Long-Term Evolution (3GPP LIE) network 10. The network 10 includes an Internet Protocol (IP) Connectivity Access Network (IP-CAN) 100 and an IP Packet Data Network (IP-PDN) 1001. The IP-CAN 100 generally includes: a serving gateway (SGW) 101; a packet data network (PDN) gateway (POW) 103; a policy and charging rules function (PCRF) 106; a mobility management entity (MME) 108 and E-UTRAN Node B (eNB) 105 (i.e., base station, for the purposes herein the terms base station and eNB may be used interchangeably). Although not shown, the IP-PDN 1001 portion of the EPS may include application or proxy servers, media servers, email servers, etc.
Within the IP-CAN 100, the eNB 105 is part of what is referred to as an Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (EUTRAN), and the portion of the IP-CAN 100 including the SGW 101, the PGW 103, the PCRF 106, and the MME 108 is referred to as an Evolved Packet Core (EPC). Although only a single eNB 105 is shown in FIG. 1, it should be understood that the EUTRAN may include any number of eNBs. Similarly, although only a single SGW, PGW and MME are shown in FIG. 1, it should be understood that the EPC may include any number of these core network elements.
The eNB 105 provides wireless resources and radio coverage for one or more user equipments (UEs) 110. That is to say, any number of UEs 110 may be connected (or attached) to the eNB 105. The eNB 105 is operatively coupled to the SGW 101 and the MME 108.
The SGW 101 routes and forwards user data packets, while also acting as the mobility anchor for the user plane during inter-eNB handovers of UEs. The SGW 101 also acts as the anchor for mobility between 3rd Generation Partnership Project Long-Term Evolution (3GPP LTE) and other 3GPP technologies. For idle UEs 110, the SGW 101 terminates the downlink data path and triggers paging when downlink data arrives for UEs 110.
The PGW 103 provides connectivity between UE 110 and the external packet data networks (e.g., the IP-PDN) by being the point of entry/exit of traffic for the UE 110. As is known, a given UE 110 may have simultaneous connectivity with more than one PGW 103 for accessing multiple PDNs.
The PGW 103 also performs policy enforcement, packet filtering for UEs 110, charging support, lawful interception and packet screening, each of which are well-known functions. The PGW 103 also acts as the anchor for mobility between 3GPP and non-3GPP technologies, such as Worldwide Interoperability for Microwave Access (WiMAX) and 3rd Generation Partnership Project 2 (3GPP2 (code division multiple access (CDMA) 1× and Enhanced Voice Data Optimized (EvDO)).
Still referring to FIG. 1, eNB 105 is also operatively coupled to the MME 108. The MME 108 is the control-node for the EUTRAN, and is responsible for idle mode UE 110 paging and tagging procedures including retransmissions. The MME 108 is also responsible for choosing a particular SGW for a UE during initial attachment of the UE to the network, and during intra-LTE handover involving Core Network (CN) node relocation. The MME 108 authenticates UEs 110 by interacting with a Home Subscriber Server (HSS), which is not shown in FIG. 1.
Non Access Stratum (NAS) signaling terminates at the MME 108, and is responsible for generation and allocation of temporary identities for UEs 110. The MME 108 also checks the authorization of a UE 110 to camp on a service provider's Public Land Mobile Network (PLMN), and enforces UE 110 roaming restrictions. The MME 108 is the termination point in the network for ciphering/integrity protection for NAS signaling, and handles security key management.
The MME 108 also provides control plane functionality for mobility between LTE and 2G/3G access networks with an interface from the SGSN (not shown) terminating at the MME 108.
The Policy and Charging Rules Function (PCRF) 106 is the entity that makes policy decisions and sets charging rules. It has access to subscriber databases and plays a role in the 3GPP architecture as specified in 3GPP TS 23.203 “Policy and Charging Control Architecture.”
FIG. 2 illustrates a conventional E-UTRAN Node B (eNB) 105. The eNB 105 includes: a memory 225; a processor 210; a scheduler 215; wireless communication interfaces 220; radio link control (RLC) buffers 230 for each bearer; and a backhaul interface 235. The processor 210 may also be referred to as a core network entity processing circuit, an EPC entity processing circuit, etc. The processor 210 may consist of one or more core processing units, either physically coupled together or distributed. The processor 210 controls the function of eNB 105 (as described herein), and is operatively coupled to the memory 225 and the communication interfaces 220. While only one processor 210 is shown in FIG. 2, it should be understood that multiple processors may be included in a typical eNB 105. The functions performed by the processor may be implemented using hardware. Such hardware may include one or more Central Processing Units (CPUs), digital signal processors (DSPs), application-specific-integrated-circuits, field programmable gate arrays (FPGAs) computers or the like. The term processor, used throughout this document, may refer to any of these example implementations, though the term is not limited to these examples. With a Virtual Radio Access Network (VRAN) architecture various functions eNB components may be distributed across multiple processing circuits and multiple physical nodes within VRAN cloud.
The eNB 105 may include one or more cells or sectors serving UEs 110 within individual geometric coverage sector areas. Each cell individually may contain elements depicted in FIG. 2. Throughout this document the terms eNB, cell or sector shall be used interchangeably.
Still referring to FIG. 2, the wireless communication interfaces 220 include various interfaces including one or more transmitters/receivers connected to one or more antennas to transmit/receive wirelessly control and data signals to/from UEs 110. Backhaul interface 235 is the portion of eNB 105 that interfaces with SGW 101, MME 108, other eNBs, or interface to other EPC network elements and/or RAN elements within IP-CAN 100. The scheduler 215 schedules control and data communications that are to be transmitted and received by the eNB 105 to and from UEs 110. The memory 225 may buffer and store data that is being processed at eNB 105, transmitted and received to and from eNB 105.
Every Transmission Time Interval (TTI), typically equal to 1 millisecond, the scheduler 215 may allocate a certain number of Physical Resource Blocks (PRBs) to different bearers carrying data over the wireless link in the Downlink direction (i.e., transmitting buffered data, located in Radio Link Control (RLC) buffer 230, from eNB 105 to UE 110) and Uplink direction (i.e., receiving data at eNB 105 from UE 110, which is received over wireless interface 220 and subsequently forwarded to the SGW 101 over backhaul 235). A “bearer” may be understood to be a virtual link, channel or data flow used to exchange information for one or more applications on the UE 110. The scheduler 215 may determine Modulation and Coding Schema (MCS) that may define how many bits of information may be packed into the allocated number of PRBs. The latter is defined by the 3GPP TS36.213 tables 7.1.7.1-1 and 7.1.7.2.1-1 (the contents of which is incorporated by reference in its entirety), where MCS is defined by a number between 0 and 28, where higher MCS values indicate that more bits may be packed in the allocated number of PRBs. The tables 7.1.7.1-1 and 7.1.7.2.1-1 include a lookup table for a number of bits of data that may be included in PRBs sent per TTI for a given allocated number of PRBs and a MCS value. MCS is computed by the scheduler using Channel Quality Indicator (CQI) values reported by the UE 110 that in turn may be derived from measured UE 110 wireless channel conditions in the form of Signal to Interference and Noise Ratio (SINR).
Scheduler 215 may make PRB allocation decisions based upon a Quality of Service (QoS) Class Identifier (QCI), which represents traffic priority hierarchy. There are nine QCI classes currently defined in LTE, with 1 representing highest priority and 9 representing the lowest priority. QCIs 1 to 4 are reserved for Guaranteed Bitrate (GBR) classes for which the scheduler maintains certain specific data flow QoS characteristics. QCIs 5 to 9 are reserved for various categories of Best Effort traffic.
While the scheduler 215 operations are not standardized, there may be certain generic types of schedulers that may generally be accepted. Examples include strict priority scheduler (SPS) and proportional weighted fair share scheduler (PWFSS). Both types try to honor GBR needs first by allocating dedicated resources to meet whenever possible the GBR bearer throughput constraints while leaving enough resources to maintain certain minimal data traffic for non-GBR classes. The SPS allocates higher priority classes with the resources that may be needed (except for a certain minimal amount of resources to avoid starving lower priority classes), and lower priority classes generally receive the remaining resources. The PWFSS gives each non-GBR QCI class certain weighted share of resources, that may not be exceeded unless unutilized resources are available.
Conventionally, data traffic of over the top mobile applications run on UEs is predominantly carried over a network using best efforts (BE) bearers. The term “best efforts” generally indicates that the bearer traffic does not enjoy a guaranteed bit rate, and the bearer therefore does not offer a guaranteed Quality of Service (QoS). However, different over the top mobile applications often have differing QoS needs and/or requirements. Having the eNB 105 be aware of the ‘application type context’ for an application traffic carried over a specific BE bearer to a UE, such as knowing whether the bearer is carrying a HTTP Adaptive Streaming (HAS) video on demand, a live video broadcast, a live conversational video, a large file transfer protocol (ftp) application, web browsing search, email data, an intermittent ftp application (for instance), may successfully enable a variety of techniques that may be used to improve end user Quality of Experience (QoE) for the specific mobile application. The term ‘application type context’ may be considered synonymous with the terms ‘application type’ and ‘application context type,’ which are used interchangeably throughout this document.
An example of a technique used to improve QoE may include a bearer context type aware resource allocation that may be implemented by eNB scheduler 215, where different scheduling policies may be applied to a BE bearer depending upon the application context that the bearer carries. Such scheduling policy differentiation may be especially beneficial under congestion conditions.
Conventionally, an application context type of bearer traffic may be obtained by applying deep packet inspection (DPI). The Open System Interconnection (OSI) model partitions communication system into 7 conceptual layers. Starting from the bottom, these layers are: Physical, Data link, Networking, Transport, Session, Presentation, and Application. The data packets in the network contain a layer of headers that allow routing and processing of the packets. The outer-most header corresponds to the lowest layer. In the IP network, packets are routed using the Internet Protocol (IP) header that represents the Networking layer. DPI generally involves inspecting and classifying application IP packet headers that are located beyond an IP header layer (i.e., packet headers that belong to OSI layers 4-7, starting from Transport layer). The Transport layer 4 may typically be represented by Transmission Control Protocol (TCP) or User Datagram Protocol (UDP) headers and may be responsible for an order delivery and integrity verification of application session packets. In the case of TCP, the Transport layer 4 may also responsible for reliable delivery of an application session packets. The Session layer 5 provides the mechanism for opening, closing and managing a session between end-user application processes DPI techniques may classify application type and context by snooping layer 4 and layer 5 headers, including source and destination TCP and UDP port numbers in the TCP or UDP headers, and applying well known associations of the port numbers with specific applications. When such port numbers provide insufficient information, DPI can further look at Session layer headers, for example, presence of Real Time Streaming Protocol (RTSP) session headers may indicate that the data packet belongs to a live conversation video application.
DPI techniques have several significant drawbacks. First, a greater number of applications utilize end-to-end data traffic encryption (such as YouTube, Netflix, Skype, etc), and this encryption does not allow DPI techniques to be performed on the data flow at the wireless access networks, since the layers 4-7 in the IP data packets may be encrypted. Second, even when a data flow is not encrypted, adding DPI capabilities at an eNB (where the real need exists for application context type knowledge) may be costly. 3GPP currently defines PGW to host a DPI function, whereas eNB may perform a simple data flow switching from a per bearer General Packet Radio Service (GPRS) Tunneling Protocol (GTP) tunnel to an over the air bearer flow by using a single identifier field from the tunnel header. Therefore, adding a DPI function at eNB may require costly hardware upgrades. Alternatively, passing via signaling the determined application context information from PGW to eNB may also require non-trivial standards change.